Re: Dazed and Confused

[Toon van der Pas <toon@hout.vanvergehaald.nl>]

On Sun, Dec 08, 2002 at 10:22:38AM -0500, Gregory Boyce wrote:
> On Sun, 2002-12-08 at 06:59, Gilad Ben-Yossef wrote:
> > On Fri, 2002-12-06 at 16:55, Greg Boyce wrote:
> > 
> > > I have an issue that I've been trying to track down for some time, and I
> > > was hoping that someone might be able to provide me with a definitive
> > > awnser.
> > > 
> > > I work in a company with a large number of Linux machine deployed all
> > > around the country, and in some of the machines we've been seeing the
> > > following error:
> > > 
> > > Uhhuh. NMI received. Dazed and confused, but trying to continue
> > > You probably have a hardware problem with your RAM chips
> > 
> > I have had the exact same error happen a while back on a 2.2.x kernel.
> > It did not seem to hurt anything but it made the QA dept. go bonkers so
> > I've spent some time chasing it down and found out what caused it back
> > then - perhaps the same, or similar, applies to your setup as well:
> > 
> > The machines in question were Intel ISP1100 1U servers and for various
> > non important reasons I have built the kernel which they were running
> > without APM support. Now these machines have 3 small non marked buttons
> > on their front - one is the power button, one is the reset button and
> > one was a suspend button. 
> > 
> > What I found out was that whenever anyone pressed the "suspend" button
> > (usually because they meant to press the power or reset buttons and
> > missed) the error in questions was logged. It seems that APM suspend is
> > implemented (at least on those machines) as an NMI, and if you compiled
> > the kernel sans APM support the NMI handling code simply did not grok
> > that specific NMI and thus reported said error, which was otherwise
> > harmless.
> 
> Most of these machines do have Intel motherboards.  I don't recall
> seeing suspend buttons, but I'll take a look.  Thanks!

Just another datapoint:

I administer a Digitial Prioris server (Pentium II, 512MB memory),
which logs one (yes, exactly one) "Uhhuh. NMI received. Etc.." message
at boot time. After booting it _never_ logs this message again.
The machine is rock stable; it currently has an uptime of 19 months
and is humming along nicely. It runs a pristine 2.2.19 kernel, with
the following patches applied:

	raw-2.2.18.FULL.diff
	linux-2.2.19-reiserfs-3.5.32-patch
	lvm_0.9.1_beta7

It looks like something is producing exactly one NMI during the boot
process. It doesn't seem to be a hardware problem.
Could it be something SMP-related? (the machine runs with one CPU, but
the motherboard can accomodate a second CPU and the BIOS supports that)
Or some power management thing, like was suggested previously in this thread?

Regards,
Toon.
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